US4066454A - Electrophotographic light-sensitive material containing indenothiophenone or its derivative and process of preparing indenothiophenone and its derivative - Google Patents

Electrophotographic light-sensitive material containing indenothiophenone or its derivative and process of preparing indenothiophenone and its derivative Download PDF

Info

Publication number
US4066454A
US4066454A US05/619,508 US61950875A US4066454A US 4066454 A US4066454 A US 4066454A US 61950875 A US61950875 A US 61950875A US 4066454 A US4066454 A US 4066454A
Authority
US
United States
Prior art keywords
indenothiophenone
derivative
photoconductive
electrophotographic light
mole
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US05/619,508
Inventor
Mitsuru Hashimoto
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ricoh Co Ltd
Original Assignee
Ricoh Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Ricoh Co Ltd filed Critical Ricoh Co Ltd
Application granted granted Critical
Publication of US4066454A publication Critical patent/US4066454A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07DHETEROCYCLIC COMPOUNDS
    • C07D333/00Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom
    • C07D333/50Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom condensed with carbocyclic rings or ring systems
    • C07D333/78Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom condensed with carbocyclic rings or ring systems condensed with rings other than six-membered or with ring systems containing such rings
    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07DHETEROCYCLIC COMPOUNDS
    • C07D333/00Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom
    • C07D333/02Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom not condensed with other rings
    • C07D333/04Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom not condensed with other rings not substituted on the ring sulphur atom
    • C07D333/06Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom not condensed with other rings not substituted on the ring sulphur atom with only hydrogen atoms, hydrocarbon or substituted hydrocarbon radicals, directly attached to the ring carbon atoms
    • C07D333/12Radicals substituted by halogen atoms or nitro or nitroso radicals
    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03GELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/02Charge-receiving layers
    • G03G5/04Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
    • G03G5/06Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor characterised by the photoconductive material being organic
    • G03G5/0622Heterocyclic compounds
    • G03G5/0624Heterocyclic compounds containing one hetero ring
    • G03G5/0627Heterocyclic compounds containing one hetero ring being five-membered
    • G03G5/0629Heterocyclic compounds containing one hetero ring being five-membered containing one hetero atom

Definitions

  • Electrophotographic light-sensitive materials comprise an electroductive support with a photoconductive layer formed thereon.
  • the principle of an electrophotographic process is that an electrostatic latent image is produced by image-wise exposure of a charged photoconductive layer and the image is then developed by a developer or toner (in liquid or powder form) which is electrically precipitated on the latent image to form a visible image.
  • inorganic photoconductors such as photoconductive zinc oxide or selenium are used.
  • an organic photoconductive compound e.g. a photoconductive polymer such as poly-N-vinylcarbazole in place of the inorganic photoconductors has been proposed.
  • the advantages of organic photoconductive compounds are transparency and mechanical flexibility.
  • dyestuff sensitizers are added to the organic photoconductive compounds.
  • Such dyestuffs as have been previously employed are generally not stable and bleach out quickly so that the organic photoconductive compounds lose their sensitivity in the visible region.
  • electrophotographic light-sensitive materials prepared utilizing organic photoconductive compounds containing dyestuff sensitizers are of limited practical use.
  • an object of the present invention to provide stable sensitizers and an improved electrophotographic light-sensitive product containing such stable sensitizers.
  • the present invention relates to electrophotographic light-sensitive materials having a photoconductive layer formed on an electroconductive support, the photoconductive layer comprising an organic photoconductive compound such as a photoconductive monomer or polymer and indenothiophenone or a derivative thereof as a sensitizer, and a process of preparing indenothiophenone and its derivatives.
  • electrophotographic light-sensitive material comprises an electroconductive support and a photoconductive layer formed on the support.
  • the electrophotographic light-sensitive materials of the present invention are characterized in that the photoconductive layer comprises an organic photoconductive compound sensitized with indenothiophenone or a nitrated derivative thereof of the following general formulas, i.e. indenothiophenone or its derivatives are used as sensitizer for the organic photoconductive compound.
  • the photoconductive layer comprises an organic photoconductive compound sensitized with indenothiophenone or a nitrated derivative thereof of the following general formulas, i.e. indenothiophenone or its derivatives are used as sensitizer for the organic photoconductive compound.
  • R 1 , R 2 , R 3 , R 4 , R 5 and R 6 are hydrogen or nitro groups.
  • the electrophotographic light-sensitive materials of the present invention are prepared by forming a photoconductive layer on an electroconductive support, the photoconductive layer comprising any of a variety of organic photoconductive monomers such as N-vinylcarbazole or organic photoconductive polymers such as poly-N-vinylcarbazole and indenothiophenone or its nitro substituted derivative.
  • organic photoconductive monomers such as N-vinylcarbazole or organic photoconductive polymers such as poly-N-vinylcarbazole and indenothiophenone or its nitro substituted derivative.
  • Indenothiophenone or its derivative are typically utilized in an amount of from 0.01 to 1.2 moles, preferably from 0.1 to 1 mole per mole of the organic photoconductive monomer or per monomeric unit of the organic photoconductive polymer (monomeric unit of an organic photoconductive polymer represents 1 mole of the polymer).
  • Organic photoconductive compounds for use in accordance with the present invention are as follows:
  • Preferred organic photoconductive polymers include poly-N-vinylcarbazole, chlorinated or brominated poly-N-vinylcarbazole, polyvinylpyrene, polyvinylnaphthalene, polyvinylanthracene, poly-9-vinylfluorene, poly-1-arylimidazole and poly-P-phenylene-1,3,4-oxadiazole.
  • Preferred organic photoconductive monomers include N-vinylcarbazole, N-ethylcarbazole, anthracene and pyrene.
  • poly-N-vinylcarbazole and chlorinated or brominated poly-N-vinylcarbazole are preferably used as an organic photoconductive compound.
  • Suitable electroconductive supports which may be used in the present invention include, for example, metallic sheets such as aluminium foil and synthetic resin sheets coated with a layer of aluminium.
  • Electrophotographic light-sensitive materials in accordance with the present invention can be produced, for example, as follows:
  • indenothiophenene or its derivative is mixed with 1 mole of the organic photoconductive monomer or monomeric unit of the organic photoconductive polymer and the mixture is dissolved in an organic solvent such as tetrahydrofuran or dioxane to prepare a light-sensitive solution.
  • an organic solvent such as tetrahydrofuran or dioxane
  • Polyester resin, novolak resin or acrylic resin may, if desired, be added to this solution.
  • polychlorobiphenyl may be added to this solution.
  • the resulting light-sensitive solution can then be applied to a surface of an electroconductive support, for example, using a doctor blade, left to set, and then dried.
  • a light-sensitive solution containing a photoconductive composition for use in the production of a photoconductive layer was prepared from the following ingredients:
  • This light-sensitive solution was applied as a coat on an aluminium layer on a polyester resin film (thickness: 75 ⁇ ), using a doctor blade set at a 200 ⁇ gap, and then dried in a desiccator holding silica gel to evaporate a solvent, and further dried at a temperature of 60° C for about 10 minutes and at a temperature of 120° C for about 2 minutes.
  • a photoconductive layer having a thickness of 13 ⁇ to 14 ⁇ was formed on the aluminium layer.
  • the sensitivity of the electrophotographic light-sensitive material (No. 1) of the present invention thus obtained was evaluated as follows:
  • the material obtained above was divided into two parts.
  • the photoconductive layer was negatively or positively charged by a corona discharge of about -6 kV (discharge current: 6 ⁇ Amp) or +6 kV (discharge current: 4 ⁇ Amp) for 20 seconds to obtain a surface electric potential Vdo and then subjected to dark decay for 20 seconds to obtain a surface residual potential Vpo.
  • This charged light-sensitive material was exposed to a tungusten filament lamp whose illuminance at the surface of the light-sensitive layer was adjusted to be 20 lux.
  • the time (seconds) required to reduce the surface electric potential to one half or one fifth of the residual surface potential Vpo were measured by using rotary sector type electrometer.
  • the amounts of exposure, El/2 (lux.sec) and El/5 (lux.sec), required to reduce the surface electric potential to one half and one fifth of Vpo are calculated by "20 lux ⁇ time (seconds)".
  • the El/2 and El/5 represent the sensitivity of the electrophotographic light-sensitive material. The lower the value of El/ 2 or El/5 the higher the sensitivity of the light-sensitive material.
  • the values of Vdo, Vpo, El/2 and El/5 are shown in the Table 1 below.
  • Electrophotographic light-sensitive material (No. 2 - No. 5) of the present invention were obtained by repeating the same procedure as that of Example 1 except that poly-N-vinylcarbazole, Polyester Adhesive 49000, tetrahydrofuran 6,8-dinitro-4H-indeno[1,2-b]thiophen-4-one and 2,6,8-trinitro-4H-indeno[1,2-b]thiophen-4-one were used in an amount as shown in the following Table 2.
  • Vdo, Vpo, El/2 and El/5 of the light-sensitive materials No. 2 - No. 5 were measured by repeating the same procedure as that of Example 1. The values obtained are shown in the Table 3 below.
  • Electrophotographic light-sensitive materials No. 6 - No. 9 were obtained by repeating the same procedure as that of Example 1 except that chlorinated or brominated poly-N-vinylcarbazole, Polyester Adhesive 49000, tetrahydrofuran and 2,6,8-trinitro-4H-indeno[1,2-b]thiophen-4-one were used in an amount as shown in the following Table 4.
  • Vdo, Vpo, El/2 and El/5 of the light-sensitive materials No. 6 - No. 9 were measured by repeating the same procedure as that of Example 1. In this case, the light-sensitive materials were only negatively charged. The values ontained are shown in the Table 5 below.
  • Electrophotographic light-sensitive materials having sensitivity to visible light can be produced with an organic photoconductive compounds having no sensitivity to visible light by adding a certain amount of indenothiophenone or its derivatives to said organic photoconductive compounds.
  • Such indenothiophenone or its derivatives can be prepared by the process as described below. ##STR4## wherein R 1 and R 2 are hydrogen atom or nitro group, X is chlorine, bromine or iodine and R is a lower alkyl group of from 1 to 4 carbon atoms.
  • the nitration as shown above is carried out in the presence of conc. H 2 SO 4 at a temperature of from 0° C to 15° C.
  • novel compound having nitro group of Formula (6) can alternatively be obtained by the following reaction process. ##STR8##
  • novel compound of the present invention as shown above is most useful as a sensitizer for organic photoconductive compounds such as poly-N-vinylcarbazole.
  • a yellowish crystalline product (m.p. 172.5° - 173.5° C) was obtained by the recrystallization of the crude product from benzene. This product was identified to be 2- ⁇ -thienyl-3,5-dinitrobenzoic acid (Formula 4) by ultimate analysis.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Plural Heterocyclic Compounds (AREA)

Abstract

Electrophotographic light-sensitive materials having a photoconductive layer formed on an electroconductive support, the photoconductive layer comprising an organic photoconductive compound (monomer or polymer) and indenothiophenone or its derivative as a sensitizer, and a process of preparing indenothiophenone and its derivatives from a benzoic acid derivative and a thiophene derivative.

Description

This is a division of application Ser. No. 716,792 filed Nov. 19, 1973 now abandoned.
BACKGROUND OF THE INVENTION
Electrophotographic light-sensitive materials comprise an electroductive support with a photoconductive layer formed thereon. The principle of an electrophotographic process is that an electrostatic latent image is produced by image-wise exposure of a charged photoconductive layer and the image is then developed by a developer or toner (in liquid or powder form) which is electrically precipitated on the latent image to form a visible image. Conventionally, for forming the photoconductive layer, inorganic photoconductors such as photoconductive zinc oxide or selenium are used. Recently, the use of an organic photoconductive compound e.g. a photoconductive polymer such as poly-N-vinylcarbazole in place of the inorganic photoconductors has been proposed. Amongst the advantages of organic photoconductive compounds are transparency and mechanical flexibility. Additionally, they are easy to form into photoconductive layers. On the other hand, they absorb light in the ultraviolet region of the spectrum, but are not sensitive to visible light. To overcome this disadvantage, i.e. to shift their absorption into the visible region of the spectrum, dyestuff sensitizers are added to the organic photoconductive compounds. Such dyestuffs as have been previously employed are generally not stable and bleach out quickly so that the organic photoconductive compounds lose their sensitivity in the visible region. As a result, electrophotographic light-sensitive materials prepared utilizing organic photoconductive compounds containing dyestuff sensitizers are of limited practical use.
It is, therefore, an object of the present invention to provide stable sensitizers and an improved electrophotographic light-sensitive product containing such stable sensitizers.
SUMMARY OF THE INVENTION
The present invention relates to electrophotographic light-sensitive materials having a photoconductive layer formed on an electroconductive support, the photoconductive layer comprising an organic photoconductive compound such as a photoconductive monomer or polymer and indenothiophenone or a derivative thereof as a sensitizer, and a process of preparing indenothiophenone and its derivatives.
In general, electrophotographic light-sensitive material comprises an electroconductive support and a photoconductive layer formed on the support.
The electrophotographic light-sensitive materials of the present invention are characterized in that the photoconductive layer comprises an organic photoconductive compound sensitized with indenothiophenone or a nitrated derivative thereof of the following general formulas, i.e. indenothiophenone or its derivatives are used as sensitizer for the organic photoconductive compound. ##STR1## wherein R1, R2, R3, R4, R5 and R6 are hydrogen or nitro groups.
These compounds are respectively designated as follows:
A 8h-indeno[2,1-b]thiophen-8-one
B 4h-indeno[1,2-b]thiophen-4-one
and nitrated derivatives thereof.
The electrophotographic light-sensitive materials of the present invention are prepared by forming a photoconductive layer on an electroconductive support, the photoconductive layer comprising any of a variety of organic photoconductive monomers such as N-vinylcarbazole or organic photoconductive polymers such as poly-N-vinylcarbazole and indenothiophenone or its nitro substituted derivative. Indenothiophenone or its derivative are typically utilized in an amount of from 0.01 to 1.2 moles, preferably from 0.1 to 1 mole per mole of the organic photoconductive monomer or per monomeric unit of the organic photoconductive polymer (monomeric unit of an organic photoconductive polymer represents 1 mole of the polymer).
Indenothiophenone and its derivatives for use in accordance with the present invention are shown by structural formulas as follows: ##STR2##
Organic photoconductive compounds for use in accordance with the present invention are as follows:
Preferred organic photoconductive polymers include poly-N-vinylcarbazole, chlorinated or brominated poly-N-vinylcarbazole, polyvinylpyrene, polyvinylnaphthalene, polyvinylanthracene, poly-9-vinylfluorene, poly-1-arylimidazole and poly-P-phenylene-1,3,4-oxadiazole.
Preferred organic photoconductive monomers include N-vinylcarbazole, N-ethylcarbazole, anthracene and pyrene.
However, poly-N-vinylcarbazole and chlorinated or brominated poly-N-vinylcarbazole are preferably used as an organic photoconductive compound.
Suitable electroconductive supports which may be used in the present invention include, for example, metallic sheets such as aluminium foil and synthetic resin sheets coated with a layer of aluminium.
Electrophotographic light-sensitive materials in accordance with the present invention can be produced, for example, as follows:
From about 0.1 to about 1 mole of indenothiophenene or its derivative is mixed with 1 mole of the organic photoconductive monomer or monomeric unit of the organic photoconductive polymer and the mixture is dissolved in an organic solvent such as tetrahydrofuran or dioxane to prepare a light-sensitive solution. Polyester resin, novolak resin or acrylic resin may, if desired, be added to this solution. Furthermore, polychlorobiphenyl may be added to this solution. The resulting light-sensitive solution can then be applied to a surface of an electroconductive support, for example, using a doctor blade, left to set, and then dried.
The following Examples are given by way of illustration only. In the Examples, 6,8-dinitro-4H-indeno[1,2-b]thiophen-4-one having Formula XI or 2,6,8-trinitro-4H-indeno[1,2-b]thiophen-4-one having Formula XII is used as a sensitizer:
EXAMPLE 1
A light-sensitive solution containing a photoconductive composition for use in the production of a photoconductive layer was prepared from the following ingredients:
______________________________________                                    
poly-N-vinylcarbazole                                                     
                   387      mg    (2m moles)                              
6,8-dinitro-4H-indeno                                                     
[1,2-b]thiophen-4-one                                                     
                   55       mg    (0.2m mole)                             
Polyester Adhesive 49000                                                  
                   38       mg                                            
(Trade mark of polyester resin                                            
sold by E. I. Du Pont de Nemours                                          
& Co., Inc.)                                                              
tetrahydrofuran    6.4      g                                             
______________________________________                                    
This light-sensitive solution was applied as a coat on an aluminium layer on a polyester resin film (thickness: 75μ), using a doctor blade set at a 200μ gap, and then dried in a desiccator holding silica gel to evaporate a solvent, and further dried at a temperature of 60° C for about 10 minutes and at a temperature of 120° C for about 2 minutes. A photoconductive layer having a thickness of 13μ to 14μ was formed on the aluminium layer.
The sensitivity of the electrophotographic light-sensitive material (No. 1) of the present invention thus obtained was evaluated as follows:
The material obtained above was divided into two parts. The photoconductive layer was negatively or positively charged by a corona discharge of about -6 kV (discharge current: 6μ Amp) or +6 kV (discharge current: 4μ Amp) for 20 seconds to obtain a surface electric potential Vdo and then subjected to dark decay for 20 seconds to obtain a surface residual potential Vpo. This charged light-sensitive material was exposed to a tungusten filament lamp whose illuminance at the surface of the light-sensitive layer was adjusted to be 20 lux. The time (seconds) required to reduce the surface electric potential to one half or one fifth of the residual surface potential Vpo were measured by using rotary sector type electrometer. The amounts of exposure, El/2 (lux.sec) and El/5 (lux.sec), required to reduce the surface electric potential to one half and one fifth of Vpo are calculated by "20 lux × time (seconds)". The El/2 and El/5 represent the sensitivity of the electrophotographic light-sensitive material. The lower the value of El/ 2 or El/5 the higher the sensitivity of the light-sensitive material. The values of Vdo, Vpo, El/2 and El/5 are shown in the Table 1 below.
              Table 1                                                     
______________________________________                                    
      Vdo        Vpo      E1/2       E1/5                                 
Charge                                                                    
      (V)        (V)      (lux·sec)                              
                                     (lux·sec)                   
______________________________________                                    
-     1030       770      26.0       72.3                                 
+      960       790      19.7       49.7                                 
______________________________________                                    
EXAMPLES 2-5
Electrophotographic light-sensitive material (No. 2 - No. 5) of the present invention were obtained by repeating the same procedure as that of Example 1 except that poly-N-vinylcarbazole, Polyester Adhesive 49000, tetrahydrofuran 6,8-dinitro-4H-indeno[1,2-b]thiophen-4-one and 2,6,8-trinitro-4H-indeno[1,2-b]thiophen-4-one were used in an amount as shown in the following Table 2.
              Table 2                                                     
______________________________________                                    
No. 2 poly-N-vinyl-                                                       
                 6,8-dinitro-4H                                           
                              Polyester                                   
                                     tetrahydro-                          
      carbazole                                                           
indeno[1,2-b]                                                             
      Adhesive   furan                                                    
      387 mg     thiophen-4-one                                           
                              49000  8.3 g                                
      (2m moles) 276 mg       58 mg                                       
                 (1m mole)                                                
No. 3 "          2,6,8-trinitro                                           
                              "      "                                    
      387 mg                                                              
4H-indeno                                                                 
      (2m moles) [1,2-b]thiophen                                          
4-one                                                                     
                 64 mg                                                    
                 (0.2m mole)                                              
No. 4 "          "            "      "                                    
      193 mg     160 mg       30 mg  2.2 g                                
      (1m mole)  (0.5m mole)                                              
No. 5 "          "            "      "                                    
      193 mg     321 mg       45 mg  4.1 g                                
      (1m mole)  (1m mole)                                                
______________________________________                                    
Vdo, Vpo, El/2 and El/5 of the light-sensitive materials No. 2 - No. 5 were measured by repeating the same procedure as that of Example 1. The values obtained are shown in the Table 3 below.
              Table 3                                                     
______________________________________                                    
             Vdo      Vpo    E1/2      E1/5                               
No  charge   (V)      (V)    (lux·sec)                           
                                       (lux·sec)                 
______________________________________                                    
2   -        710      560    15.7      31.4                               
    +        670      450    15.4      44.3                               
3   -        880      610    16.9      48.0                               
    +        800      640    12.9      34.6                               
4   -        840      510    10.3      34.3                               
    +        740      280    12.6      36.6                               
5   -        990      640     9.7      29.1                               
    +        720      390    25.4      73.4                               
______________________________________                                    
EXAMPLES 6-9
Electrophotographic light-sensitive materials No. 6 - No. 9 were obtained by repeating the same procedure as that of Example 1 except that chlorinated or brominated poly-N-vinylcarbazole, Polyester Adhesive 49000, tetrahydrofuran and 2,6,8-trinitro-4H-indeno[1,2-b]thiophen-4-one were used in an amount as shown in the following Table 4.
              Table 4                                                     
______________________________________                                    
No. 6 *1)        2,6,8-trinitro                                           
                              Polyester                                   
                                     tetrahydro-                          
      chlorinated                                                         
4H-indeno                                                                 
      Adhesive   furan                                                    
      poly-N-vinyl-                                                       
                 [1,2-b]thiophen                                          
                              4900   4.4 g                                
      carbazole                                                           
4-one 48 mg                                                               
      228 mg     321 mg                                                   
      (1m mole)  (1m mole)                                                
No. 7 "          "            "      "                                    
      228 mg     161 mg                                                   
      (1m mole)  (0.5 m mole) 34 mg  3.6 g                                
No. 8 *2)        "            "      "                                    
      brominated 321 mg       48 mg  4.4 g                                
      poly-N-vinyl-                                                       
                 (1m mole)                                                
      carbazole                                                           
      233 mg                                                              
      (1m mole)                                                           
No. 9 "          "            "      "                                    
      233 mg     161 mg       34 mg  3.1 g                                
      (1m mole)  (0.5m mole)                                              
______________________________________                                    
 *1) Chlorine is contained in a proportion of one chlorine atom per       
 monomeric unit of poly-N-vinylcarbazole.                                 
 *2) Bromine is contained in a proportion of one bromine atom per two     
 monomeric units of poly-N-vinylcarbazole.                                
Vdo, Vpo, El/2 and El/5 of the light-sensitive materials No. 6 - No. 9 were measured by repeating the same procedure as that of Example 1. In this case, the light-sensitive materials were only negatively charged. The values ontained are shown in the Table 5 below.
              Table 5                                                     
______________________________________                                    
             Vdo      Vpo    E1/2      E1/6                               
No  charge   (V)      (V)    (lux·sec)                           
                                       (lux·sec)                 
______________________________________                                    
6   -         790     560     9.1      32.0                               
7   -         910     680    10.3      35.1                               
8   -        1080     760    10.6      33.5                               
9   -        1170     860    13.4      35.5                               
______________________________________                                    
In the Examples supra, only 6,8-dinitro-4H-indeno[1,2-b]thiophen-4-one and 2,6,8-trinitro-4H-indeno[1,2-b]thiophen-4-one were used as a sensitizer. However, the values of Vdo, Vpo, El/2 and El/5 similar to those as shown in the Tables 1, 3 and 5 can be obtained by using indenothiophenone or its derivatives as shown in Formulas I - X in place of the above-mentioned two indenothiophenone derivatives in an amount of from 0.1 mole per monomeric unit of poly-N-vinylcarbazole, or chlorinated or brominated poly-N-vinylcarbazole.
Electrophotographic light-sensitive materials having sensitivity to visible light can be produced with an organic photoconductive compounds having no sensitivity to visible light by adding a certain amount of indenothiophenone or its derivatives to said organic photoconductive compounds.
4H-indeno[1,2-b]thiophen-4-one and its derivatives having the following general formula are novel: ##STR3## wherein R1, R2 and R3 are hydrogen atom or nitro group.
Such indenothiophenone or its derivatives can be prepared by the process as described below. ##STR4## wherein R1 and R2 are hydrogen atom or nitro group, X is chlorine, bromine or iodine and R is a lower alkyl group of from 1 to 4 carbon atoms.
The reaction as shown above is carried out in an organic solvent such as dimethylformamide at a temperature of from 50° C to 150° C. ##STR5## wherein R1, R2 and R are same as mentioned above.
The reaction as shown above is carried out in an aqueous solution of NaOH at a temperature of from 15° C to 60° C. ##STR6##
The reaction of ring closure as shown above is carried out in the presence of polyphosphoric acid at a temperature of from 70° C to 150° C. ##STR7##
The nitration as shown above is carried out in the presence of conc. H2 SO4 at a temperature of from 0° C to 15° C.
The novel compound having nitro group of Formula (6) can alternatively be obtained by the following reaction process. ##STR8##
The last step of the reaction as shown above may be carried out as follows: ##STR9##
The novel compound of the present invention as shown above is most useful as a sensitizer for organic photoconductive compounds such as poly-N-vinylcarbazole.
The processes of preparing 6,8-dinitro-4H-indeno[1,2-b]thiophen-4-one (Formula XI) and 2,6,8-trinitro-4H-indeno[1,2-b]thiophen-4-one (Formula XII) are shown in detail below: 13g (0.05 mole) of methyl 2-chloro-3,5-dinitrobenzoate (m.p. 193° - 195° C, Formula 1 as shown above) and 21 g (0.1 mole) of 2-iodothiophene (b.p. 71° - 73° C at 15 mm Hg, Formula 2) were dissolved in 100 ml of dimethylformamide and the solution was heated at a temperature of 70° C. To this solution was added 20 g of active copper powder (as prepared by the method disclosed in Journal of American Chemical Society Vol. 55 Page. 4219 (1933) by E. C. Kleiderer and R. Adams) over 10 minutes and the solution was stirred at a temperature of 70° C for 50 minutes. After has been cooled, the reaction product was poured into 500 ml of cold water. The precipitate thus produced was filtered off and washed with water. After water was removed from the precipitate, the precipitate was added to 500 ml of acetone. After the stirring has been continued, the solution was filtered. The filtrate was treated with active carbon, and then filtered. The filtrate was condensed to obtain a crude product. 13.1 g of a yellowish crystalline product (m.p. 134° - 135° C) was obtained in a 85% yield by recrystallization of the crude product from ethyl alcohol. This product was identified to be methyl 2-α-thienyl-3,5-dinitrobenzoate (Formula 3) by ultimate analysis.
______________________________________                                    
Analysis:                                                                 
        C(%)     H(%)     N(%)      S(%)                                  
______________________________________                                    
Calculated for                                                            
          46.75      2.61     9.09    10.41                               
 C.sub.12 H.sub.8 N.sub.2 O.sub.6 S                                       
Found     46.86      2.60     9.02    10.61                               
______________________________________                                    
The presence of carbonyl group was proved by infrared absorption spectrum at 1730 cm-1.
23.6 g of methyl 2-α-thienyl-3,5-dinitrobenzoate (Formula 3) thus obtained was dissolved in 100 ml of dioxane and to this solution was added an aqueous solution of NaOH (6 g of NaOH in 200 ml of water) and the stirring was continued for 3 hours. To this solution was added a small amount of active carbon and the solution was filtered. To the filtrate was added a cold water and the filtrate was neutralized with 6H-HCl with cooling to obtain a yellowish crystalline product. The crystalline product was filtered off and washed with water, and then dried. A crude product (m.p. 171° - 172° C) was obtained in a yield of 215 g. A yellowish crystalline product (m.p. 172.5° - 173.5° C) was obtained by the recrystallization of the crude product from benzene. This product was identified to be 2-α-thienyl-3,5-dinitrobenzoic acid (Formula 4) by ultimate analysis.
______________________________________                                    
Analysis:                                                                 
        C(%)     H(%)     N(%)      S(%)                                  
______________________________________                                    
Calculated for                                                            
          44.90      2.06     9.52    10.90                               
 C.sub.11 H.sub.6 N.sub.2 O.sub.6 S                                       
Found     44.65      2.10     9.65    10.72                               
______________________________________                                    
The presence of carbonyl group and hydroxyl group were respectively proved by infrared absorpotion spectrum at 1730 cm-1 and 3000 cm-1.
To 2 g of 2-α-thienyl-3,5-dinitrobenzoic acid (Formula 4) was added 60 g of polyphosphoric acid and the mixture was heated at a temperature of from 130° C to 140° C. After colling, the reaction mixture was poured into 200 ml of cold water. The precipitate thus produced was filtered off and washed with an aqueous solution of sodium carbonate and water, and then dried. 18 g of crude product (m.p. 206° - 207.5° C) was obtained in a 95% yield. An orange-brownish crystalline product (m.p. 209.5° - 210.0° C) was obtained by the recrystallization of the crude product from tetrahydrofuran. This product was identified to be a novel compound of 6,8-dinitro-4H-indeno[1,2-b]thiophen-4-one (Formula XI) by ultimate analysis.
______________________________________                                    
Analysis:                                                                 
        C(%)     H(%)     N(%)      S(%)                                  
______________________________________                                    
Calculated for                                                            
          47.83      1.46     10.11   11.61                               
 C.sub.11 H.sub.4 N.sub.2 O.sub.5 S                                       
Found     47.65      1.57     10.01   11.62                               
______________________________________                                    
The presence of carbonyl group was proved by infrared absorption spectrum at 1730 cm-1.
1.5 g 6,8-dinitro-4H-indeno[1,2-b]thiophen-4-one (Formula XI) was dissolved in 30 ml of conc. H2 SO4 and to this solution was added drop-wise with stirring, 5 ml of HNO3 (S.G. 1.38), at a temperature of from 5° C to 10° C, over 30 minutes. Stirring was continued at this temperature for 1.5 hours. This solution was poured into 200 ml of cold water. A yellowish crystalline product separated from the solution. The crude product was filtered and washed with water and then dried. 1.4 g of a yellowish needle-like crystalline product (m.p. 233° - 223.5° C) was obtained in a 80.5% yield by the recrystallization of the crude product from dioxane-ethyl alcohol. This product was identified to be a novel compound of 2,6,8-trinitro-4H-indeno[1,2-b]thiophen-4-one (Formula XII) by ultimate analysis.
______________________________________                                    
Analysis:                                                                 
        C(%)     H(%)     N(%)      S(%)                                  
______________________________________                                    
Calculated for                                                            
          41.16      0.93     13.08    9.98                               
 C.sub.11 H.sub.3 N.sub.3 O.sub.7 S                                       
Found     40.90      1.32     12.90   10.23                               
______________________________________                                    
The presence of carbonyl group was proved by infrared absorption spectrum at 1730 cm-1.
Derivatives of 8H-indeno[2,1-b]thiophen-8-one are disclosed in the following literatures:
D. W. H. MacDowell and Timothy B. Patrick; Journal of Organic Chemistry 32(8) 2441 - 2445 (1967)
Rene Dabard and Jean Y. Le Bihan; C.R. Adademy Science Ser. C. 271(4) 311 - 313 (1970).

Claims (4)

I claim:
1. An electrophotographic light-sensitive material having a photoconductive layer formed on an electroconductive support, the photoconductive layer comprising a photoconductive material selected from the group consisting of organic photoconductive monomers and organic photoconductive polymers, and from 0.01 to 1.2 mole per mole of organic photoconductive monomer or per monomeric unit of the organic photoconductive polymer of indenothiophenone or a derivative thereof of the formulas: ##STR10## wherein R1, R2, R3, R4, R5 and R6 are hydrogen or nitro groups.
2. An electrophotographic light-sensitive material according to claim 1 wherein
indenothiophenone or its derivative is present in an amount of from 0.1 to 1 mole per mole of the organic photoconductive monomer or per monomeric unit of the organic photoconductive polymer.
3. An electrophotographic light-sensitive material according to claim 1 wherein
the indenothiophenone derivative is 6,8-dinitro-4H-indeno[1,2-b]thiophen-4-one.
4. An electrophotographic light-sensitive material according to claim 1 wherein
the indenothiophenone derivative is 2,6,8-trinitro-4H-indeno[1,2-b]thiophen-4-one.
US05/619,508 1973-11-19 1975-10-03 Electrophotographic light-sensitive material containing indenothiophenone or its derivative and process of preparing indenothiophenone and its derivative Expired - Lifetime US4066454A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US41679273A 1973-11-19 1973-11-19

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US41679273A Division 1973-11-19 1973-11-19

Publications (1)

Publication Number Publication Date
US4066454A true US4066454A (en) 1978-01-03

Family

ID=23651318

Family Applications (1)

Application Number Title Priority Date Filing Date
US05/619,508 Expired - Lifetime US4066454A (en) 1973-11-19 1975-10-03 Electrophotographic light-sensitive material containing indenothiophenone or its derivative and process of preparing indenothiophenone and its derivative

Country Status (1)

Country Link
US (1) US4066454A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0466094A2 (en) * 1990-07-10 1992-01-15 Canon Kabushiki Kaisha Electrophotographic photosensitive member

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3287122A (en) * 1961-07-24 1966-11-22 Azoplate Corp Process for the sensitization of photoconductors
US3311471A (en) * 1963-10-23 1967-03-28 Eastman Kodak Co Photographic reproduction processes and materials therefor
US3408190A (en) * 1966-03-15 1968-10-29 Xerox Corp Electrophotographic plate and process employing photoconductive charge transfer complexes
US3871883A (en) * 1972-12-28 1975-03-18 Ricoh Kk Electrophotographic photoconductive layer comprising an organic photoconductor and a dicyanomethylene-indenothiophene sensitizer
US3905814A (en) * 1972-09-15 1975-09-16 Oce Van Der Grinten Nv Dibenzothiophene oxide or dioxide sensitizers for organic photoconductors

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3287122A (en) * 1961-07-24 1966-11-22 Azoplate Corp Process for the sensitization of photoconductors
US3311471A (en) * 1963-10-23 1967-03-28 Eastman Kodak Co Photographic reproduction processes and materials therefor
US3408190A (en) * 1966-03-15 1968-10-29 Xerox Corp Electrophotographic plate and process employing photoconductive charge transfer complexes
US3905814A (en) * 1972-09-15 1975-09-16 Oce Van Der Grinten Nv Dibenzothiophene oxide or dioxide sensitizers for organic photoconductors
US3871883A (en) * 1972-12-28 1975-03-18 Ricoh Kk Electrophotographic photoconductive layer comprising an organic photoconductor and a dicyanomethylene-indenothiophene sensitizer

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0466094A2 (en) * 1990-07-10 1992-01-15 Canon Kabushiki Kaisha Electrophotographic photosensitive member
US5484673A (en) * 1990-07-10 1996-01-16 Canon Kabushiki Kaisha Electrophotographic photosensitive member
EP0757292A1 (en) * 1990-07-10 1997-02-05 Canon Kabushiki Kaisha Electrophotographic photosensitive member
US5677095A (en) * 1990-07-10 1997-10-14 Canon Kabushiki Kaisha Electrophotographic photosensitive member
EP0466094B1 (en) * 1990-07-10 1999-03-24 Canon Kabushiki Kaisha Electrophotographic photosensitive member

Similar Documents

Publication Publication Date Title
US4403025A (en) Electrophotographic photoreceptor
US4075012A (en) Intrachain charge transfer complexes use in electrophotographic imaging
JPS637218B2 (en)
JPH0251162A (en) Electrophotographic sensitive body
US3526502A (en) Electrophotographic material
US4007043A (en) Photoconductive elements with copolymer charge transport layers
US3871883A (en) Electrophotographic photoconductive layer comprising an organic photoconductor and a dicyanomethylene-indenothiophene sensitizer
US4229510A (en) Photoconductive polymer material of N-alkylphenothiazine and formaldehyde
US3244517A (en) Electrophotographic process
US3867140A (en) Organic photoconductor-(mononitro-2-aza-fluorenylidene)malononitrile charge transfer complex
US4066454A (en) Electrophotographic light-sensitive material containing indenothiophenone or its derivative and process of preparing indenothiophenone and its derivative
US3943108A (en) Photoconductive composition of an aldehyde condensate
US3796572A (en) Electrophotographic light-sensitive material
US3987060A (en) Dicyanomethylene-indeno thiophene and derivatives
US3549361A (en) Electrophotographic compositions and elements
US4025710A (en) Intrachain charge transfer complexes
US3813248A (en) Organic photoconductive composition comprising an organic photoconductive compound and a sensitizing compound having an active methylene group
US3765882A (en) Heterocyclic photoconductor containing o, s or se
US3909260A (en) Sensitizer for use in electrophotographic light-sensitive material
US3607257A (en) Photoconductive compositions and elements
US3615416A (en) 9 10-substituted acridines as sensitizers in electrophotographic systems
JPH09278723A (en) Amine compound containing hydroxyl group and its production intermediate
US3533786A (en) Photoconductive elements containing ionic cycloheptenyl photoconductive compounds
US4137413A (en) 1,3,7-Trinitrophenazine-5-oxide
US4055421A (en) Sensitizer for photoconductive sensitive material